Blade1001 here from the MPC Club forum. I now have my Netgear 550, and I have the same problem. When I perform the speed test on the Netgear the results are inconsistent, ranging from 28mbps down to 10mbps, none of which is enough for a reliable HD stream!
I had the same issue with my TViX 6500 over SMB from the DroboFS, just stuttering and lock-ups. Only way I managed to get the TViX smooth was by using the FUPPES Upnp app on the DroboFS (being as all attempts to get NFS working on it - by using the UnFSD app - all failed miserably).
As far as I can ascertain, my DroboFS is little more use than a paper weight! And an expensive one at that! I’m almost 80% of the way towards making the decision to ditch the useless Drobo and make up a “home brew” UnRaid server, which by all accounts provides a combination of the most flexible, most cost effective and fastest solution out there!